1. Field of the Invention
The present invention relates to a rotating and positioning tool for axially symmetrical workpieces, especially steering tie rods in motor vehicles, with a housing that has a recess for inserting the workpiece and that accommodates a clamping mechanism that is powered, that engages the outside of the workpiece, and that can be rotated around the longitudinal axis of the workpiece.
The axially symmetrical workpieces are in particular pipes or rods with a cylindrical surface that have to be rotated around their longitudinal axis, to position them for instance, even though their ends are inaccessible. It must accordingly be possible to grasp the workpiece at any desired accessible point and to rotate it. Furthermore, it is not assumed herein that the point has been specially worked or that its structure makes it an appropriate positive grasping point.
Lack of true, cross-sectional tolerances, and surface irregularities of the type common in castings for example should not affect the positioning process in any way. The invention makes it possible to reliably secure workpieces with non-circular, elliptical or polygonal for example, cross-sections.
The connection between the workpiece and the tool must be unobjectionable in order to allow the reliable transmission of high torques.
Automatic rotation of the workpiece also necessitates a controlled drive mechanism governed by signals, generated by a measuring system for instance, in such a way that the tool can be integrated into a partly or fully automatic process, finishing for example. It must also be possible to operate the tool manually.
An especially important application of a rotating and positioning tool that will satisfy the aforesaid demands is the positioning of steering tie rods in motor vehicles.
2. Discussion of Prior Art
A rotating and positioning tool of the aforementioned type is known from German Pat. No. 2 644 865. The rotating clamping mechanism exhibits three compression rollers, at least one of them driven, that can be forced against the workpiece. The drawback of this known rotating and positioning tool is that the torques that have to be transmitted are relatively slight, even when the compression forces are strong, and are inadequate in consideration of the irregularities in the surface of the workpiece.